This is an original Sparklets brand CO2 capsule/charger key, manufactured in the late 20's to early 30's from a heavy metal alloy, and designed to fit the Sparklets Type C glass bodied soda syphons (although this key will fit any Sparklets syphon from the 1920's through to the 1980's) which has been carefully plated with a mirror-like coating of chrome.  This charger key will fit the modern C (8 gram) sized CO2 capsule, which are a widely standard size available to this day.